Cancer has become the second major disease threatening people's health. However, people do not have any good method for treatment of cancer. It is known that there are over 30,000 genes in human genome, while there are about 200 targets for drugs. The number of theoretical targets predicted on basis of genome is about 2000, while there are about 10,000 medicines available in clinical in about 1200 different structure types. Therefore, now there are a large number of compounds targeting at various target proteins of different functions and structures in human body. Furthermore, these commercially available drugs have demonstrated to have a confirmed safety and good bioavailability.
Anagrelide, also known as Agrylin, whose structural formula is 6,7-dichloro-1,5-dihydro-imidazo [2,1-b] quinazolin-2 (3H)-one, came into the market in March of 1997 in US as a phosphodiesterase inhibitor useful for treatment of anti-thrombocythemia. As early as in 1979, US scientists J. S. Fleming and J. P. Buyniski found a novel small molecule compound BL-4162A (Anagrelide) exhibited a significant anti-thrombotic function in animal experiments. Subsequent studies disclosed that Anagrelide was capable of inhibiting phosphodiesterase (PDE) activity, increasing intracellular cAMP content, thus affecting blood cell functions such as proliferation, maturation, and differentiation. However, functions and applications of Anagrelide in the treatment of tumor have not been reported. Therefore, there is no application of Anagrelide or the derivatives thereof in treatment of tumor.
Since there is absence of satisfying and effective tumor treating method, the development of a novel anti-tumor medicine is urgently needed in the field.